Quartz spoke with Pratt in 2016, soon after his joining Toyota and creating its $1 billion research institute. Here’s what he had to say about weighing the lives that autonomous vehicles will save against the ones it will invariably take as it improves, long before a robot car killed someone:

We have grown up, for whatever reason, as a society expecting machines to be flawless. So if a human being makes a mistake, and someone gets hurt, somehow we accept that. Around 30,000 people in the US lose their lives to cars each year. So you divide 30,000 by about 300 days in the year (plus or minus), and what do you come up with? 100 people every day. So if 100 people lost their lives in the US every day due to crime, due to terrorism, or accidents of any sort, the news would be going crazy. And yet 100 people every day lose their lives to cars and we somehow accept it.

We’re going to introduce technology which will drastically lower the number of deaths per year that occur. But some of the time, when that technology is in charge, an accident will still occur. When that happens, how will people view the occasional accidents that do occur? And unfortunately right now—or perhaps, fortunately—we have incredibly stringent expectations of performance and reliability for anything that’s mechanical. And so the hardest part of the work we have to do is to develop technology that will work at that level of expected reliability.

It may be that what we need to do is to get society to understand that even though the overall statistics are getting tremendously better, that there are still occasions when the machine is going to be to blame, and we somehow need to accept that. Because if we stop using the new software, we won’t get the benefit of this drastic average reduction.

This post has been updated with comments from Boston’s transportation department.

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